The effects of the spin–orbit coupling strength of the two configurations of rare-earth ions on the magneto-optical properties in garnets

Abstract

The effects of the spin–orbit (SO) interaction strength of the ground and excited configurations of rare-earth ions on the paramagnetic and diamagnetic Faraday rotation (FR) spectra in Ce-substituted yttrium iron garnets (YIG) are studied on the basis of quantum theory. It is found that the effect of the SO interaction strength of the ground configuration is stronger than the corresponding effect of the excited configuration. The reasons for this difference have been analysed in connection with the analysis of the large FR effect in Bi-substituted YIG.

Curie temperature, exchange integrals, and magneto-optical properties in off-stoichiometric bismuth iron garnet epitaxial films

“…11,14,16,17,19 These descriptions are based on the identification of the underlying electronic transitions either by a first-principles approach 16,19 or in terms of phenomenological diamagnetic or paramagnetic transition lines. [10][11][12][13]15,18 Following the frequency dispersion analysis presented by Helseth et al 13 and applied by Kahl et al, 18 it turns out that within the experimentally accessible spectral range of 1.7 to 3.5 eV, only two "diamagnetic transition lines" are relevant. 13,16,18 According to Zenkov et al, 16 for weakly Bi-substituted YIG the most intense transition lines correspond to a FeO 6 octahedral ͑2.78 eV͒ and a FeO 4 tetrahedral ͑3.4 eV͒ O2p-Fe 3+ chargetransfer transition.…”

“…A more detailed analysis reveals that this film not only shows an enhanced deficiency in Bi content but also an enhanced deficiency in Fe content. In the literature, the spectral variation of the magneto-optical Faraday rotation and ellipticity ͑or more precisely the off-diagonal permittivity tensor elements͒ in Bi-substituted iron garnets has been subject to intensive analysis both in terms of molecular-orbital analysis [10][11][12][13]15,18,19 and charge-transfer transitions. 11,14,16,17,19 These descriptions are based on the identification of the underlying electronic transitions either by a first-principles approach 16,19 or in terms of phenomenological diamagnetic or paramagnetic transition lines.…”

Growth parameters of Bi0.1Y2.9Fe5O12 thin films for high frequency applications

“…However, in the instance of Bi-YIG with (111) orientation, there is a substantial increase. This might be attributed qualitatively to the presence of Bi 3+ ions, which cause strong spin-orbit coupling [43][44][45] as well as electron scattering inside the lattice when the lattice mismatch (or strain) increases [46]. Our earlier study [7] revealed a clear distribution of Bi 3+ ions along (111) planes, as well as slightly larger lattice mismatch in Bi-YIG (111).…”

Is the first-order magneto-optical effect really proportional to the magnetization?

“…Our previous works illustrate the complexity of a complete theoretical analysis of such properties even if the molecular field approximation is used to describe the superexchange interactions between magnetic ions. [5][6][7] A simpler system is that of the isomorphous paramagnetic garnets where no Fe-RE superexchange interactions exist and where the magnetic interactions between RE ions are very weak ͑magnetic ordering below 1 K only͒. In this work a complete theoretical interpretation of both magnetic and MO properties ͓Faraday rotation ͑FR͔͒ is reported for a paramagnetic gallate of neodymium ͓Nd 3 Ga 5 O 12 ͑NdGaG͔͒.…”